The present invention claims priority under 35 U.S.C. xc2xa7119 of German Patent Application No. 198 37 981.1, filed on Aug. 21, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The present invention relates to a process and device for the production and packaging of material web rolls, and more particularly, to a device having a slitting station for slitting a material web into several strips, and further having a winding bed for accommodating a stack of material web rolls arranged next to one another.
2. Discussion of Background Information
In one of the final manufacturing steps, a paper web is wound into a transportable winding roll and is then packaged. It is necessary to slit the finished paper web to a certain width during this process. Paper webs are manufactured in fairly large widths of up to approximately 10 meters (m). However a consumer (e.g., a printer), only needs a roll width of up to a current maximum of approximately 3.8 m. In many cases, rolls have an even smaller width, down to approximately 0.8 m. Accordingly, the paper web is unwound from a master roll having a large width, runs first through a slitting device that produces web subsections which are then wound up into the individual winding rolls. The rolls have diameters in the range from approximately 1 to 2.5 m.
Once the material web rolls have been wound, they still must be packaged. These rolls are customarily ejected from the winding station and delivered to a packaging station, where they are wrapped in a packaging web. As soon as the rolls have been ejected, the winding station can again be prepared for the accommodation of new material web rolls (e.g., winding tubes can be inserted onto which the material web strips can be wound).
Because of long setup times required, a single winding station is not normally enough for the manufacture of material web rolls. Such a single helical winding roll packaging is described in German patent document No. DE 19535 746 C2. However, two winding stations often wastefully provide too great a capacity. Thus, the winding stations often operate with excess capacity.
The present invention provides a device and process for the production and packaging of material web rolls. The device includes a slitting station configured to slit a material web into a plurality of strips and a winding bed adapted to accommodate a stack of individual material web rolls next to one another. Also included is a packaging web dispenser adapted to travel, in at least one direction, parallel to the axis of the stack of individual material web rolls, and further adapted to dispense a packaging web at a predetermined angle to a circumferential direction of rotation of the stack of individual material web rolls. Additionally, a cutting device adapted to cut the packaging web parallel to the end faces of the material web roll may be provided.
Also, the packaging web dispenser may be adapted to travel in two directions parallel to the axis of the stack.
The packaging web dispenser may be arranged on a rail above the winding bed, and the cutting device may be also be arranged on the rail. Also, the cutting device may have a circular blade adapted to be moved at least toward the stack in a generally radial direction. Further, the circular blade may move away from the stack in a generally radial direction
Additionally, the rail may carry a loading roller which forms a nip with the stack of individual material web rolls during winding, and the nip may be adapted to accept the packaging web therethrough.
The packaging web and the material web may further travel along at least a portion of the same path.
Also, the cutting device may be formed by the slitting station. Additionally, the slitting station may include a sensor adapted to detect the passage of a leading side edge of the packaging web.
The circular blade may be further adapted to be moved away from the stack in a generally radial direction.
The process of the present invention includes winding the material web rolls about an axis, from strips created by a longitudinal slit, helically wrapping a packaging web about the circumference of the stack of material web rolls, the stack of material web rolls being in substantially the same position in which they are wound. The process also includes separating the packaging web at a position corresponding to the respective end faces of each material web roll.
The process may further include guiding the packaging web from before one roll stack end face, to past another roll stack end face, and cutting the packaging web parallel to the roll stack end faces.
Additionally, the process may include cutting the packaging web located on the circumference of the roll stack.
Further, the process may include cutting the packaging web after completion of packaging.
Also, the process may include cutting the packaging web as it is supplied, coordinating the feed rate of the packaging web with the movement of the packaging web parallel to the axis of rotation of the stack, and forming at least one separating line parallel to the end faces of the individual material web rolls.
Further, the packaging web may be passed through the same slitting device through which the material web passes.
The process may yet still further include holding together, at least in the region of a leading edge of a packaging web, adjacent packaging web sections on both sides of the separating line.
The present invention packages material web rolls in a cost-effective manner.
In the present invention, the circumference of the material web rolls lying next to one another are in the form of a horizontal stack, in the same positions as for winding, and the rolls are wrapped by a packaging web guided about the stack in a helical curve. The packaging web is separated at each position corresponding to the end faces of the material web rolls.
This configuration has several advantages. The winding station can be used to produce the circumferential packaging of the material web rolls. Not only are the material web rolls rotated during winding, but are also rotated during the application of the packaging web, which is drawn onto the circumference as the material web rolls rotate. Since this rotary drive for the material web rolls must already be used for winding, the rotary drive may also be used for creating the circumferential packaging.
The present invention also advantageously uses a special packaging web guide. Because the packaging web is wound about the stack in the form of a helix, only a single strip of packaging web is needed, regardless of the width (i.e., the axial length) of the stack. The invention may further advantageously be used when the widths of the material web rolls vary a great deal and/or are significantly larger than the width of the packaging web. With a relatively large stack, the packaging merely takes a little longer because the helical curve is longer, but the process remains the same. It is only necessary to cut the packaging web at the end faces of each material web roll so that the web rolls may be handled individually. If a number of material web rolls, for example, two, are combined in one shared package, then it is not necessary to make a cut at each end face of the material web rolls, but rather only in those locations where one wishes to separate groups of material webs from one another. Once the circumference of the material web rolls has been packaged and the material web rolls are available individually or in groups, they can be ejected from the winding station and transported to an end face packaging unit. During this transport, however, the circumference of the material web rolls is already protected so that the risk of subsequent damage during transport is kept to a minimum. At the end face packaging unit, end covers may be applied. If necessary, an edge strip can additionally be used to protect the edges of the material web roll and/or to hold the end covers in place. Application of the end covers is greatly simplified in that the circumferential packaging virtually terminates at the end faces of the material web rolls.
The packaging web may be guided completely from one end face to another end face of the stack, where the packaging web is cut parallel to the end faces. Due to the helical travel of the packaging web, the packaging may not have the same outside diameter everywhere along the stack, which can lead to problems during transport if the material web rolls are to be rolled on their circumference. However, if the packaging web is guided beyond the outer end faces and the at least three-cornered endpiece that forms thereat is cut off, this problem does not arise. It is thus not necessary to fold in an endpiece or projecting end, which would otherwise make any desired pile stacking more difficult.
The packaging web located on the circumference of the stack may cut. This feature is advantageous in that the position where cutting is necessary does not have to be changed relative to the packaging web. Thus, no additional complicated control processes are required. The position where cutting occurs is located where two material web rolls are adjacent to one another. Customarily, a gap of a few millimeters is provided at this region, into which a cutting device can enter without damaging the material web roll.
Cutting becomes especially easy when the packaging web is cut after completion of the circumferential packaging. Thus, individual packaging steps are unnecessary. First, the circumferential wrapping of the entire stack is completed. During this process, the individual bands of the packaging web, which overlap, are adhered to one another. Once the xe2x80x9csleevexe2x80x9d is finished, the individual material web rolls can again be separated in another step.
In a second embodiment, the packaging web may be cut as it is supplied, where the feed rate of the packaging web and its movement parallel to the axis of the stack""s rotation are coordinated such that a separating line is formed parallel to the respective end faces of the material web rolls. Because the packaging web is wrapped in a helix about the circumference of the stack, it is necessary to coordinate the feed rate of a packaging web dispenser parallel to the axis of rotation of the stack, with the circumferential velocity of the stack, such that the surface area of the packaging web is dispensed onto the stack in the circumferential direction of rotation. If there are additional components in the axial direction, wrinkles would otherwise form. However, this control system can be utilized in such a way that cuts or separating lines are generated such that, while the lines or cuts are diagonal relative to the packaging web, they are parallel to the end faces of the material web rolls.
Also, the packaging web may pass through the same slitting device as the material web. Thus, the packaging web for each material web roll has the same axial length as the material web roll. As a result, troublesome projecting ends, as well as uncovered sections of material web rolls are eliminated.
Adjacent packaging web sections may be held together on both sides of the separating line, at least at the region of a leading lateral edge of the packaging web. The initial application of the packaging web to the circumference of the stack is easily accomplished. Problems do not arise when the packaging web is wound about the circumference of the stack without a separating line. However, when separating lines are generated, relatively sharp triangular endpieces are created at the beginning of each packaging web section that wraps a material web roll. The handling of this xe2x80x9cendpiecexe2x80x9d requires some consideration. Handling may be facilitated by holding the two adjacent sections of the packaging web together at least at the apex distance of this endpiece (i.e., on the side edge adjacent to the stack). This xe2x80x9cholding togetherxe2x80x9d can be accomplished, for example, by not cutting the packaging web for a short distance. The xe2x80x9cholding togetherxe2x80x9d can also be accomplished in that the separating line may be formed by a perforation. Also, an adhesive strip can also be used, so that the end of one packaging web pulls the beginning of the next packaging web along with it, so to speak. The short connecting piece between adjacent packaging web sections causes no harm. It will be torn off, at the latest, when the material web rolls are ejected from the winding bed.
The packaging web dispenser is capable oftravel parallel to the axis of rotation of the stack, in two directions, and dispenses a packaging web at a predetermined angle to the circumferential direction of rotation of the stack. A cutting device is also provided, which cuts the packaging web parallel to the end faces of the material web roll.
The helical winding of the packaging web is accomplished by the packaging web dispenser dispensing the packaging web at a predetermined angle to the circumferential direction of rotation of the stack. The dispenser is laterally movable in two directions parallel to the axis of rotation of the stack. The material web rolls (or the stack) are rotated in the winding bed. Thus, the winding bed serves a dual purpose, thereby avoiding idleness of the bed. In addition, the present invention provides a relatively low-cost solution for dispensing a packaging web. Further, only one packaging web size need be kept on hand, regardless of the axial length of the material web roll stack to be packaged.
The packaging web dispenser may be arranged on a rail above the winding bed. This design has several advantages. Such a rail is already present in most material web winding stations, since winding stations generally utilize a pressure roller to generate the necessary nip pressure and the required winding tightness and hardness at the start of a winding process. However, this rail is often only used at the start of winding. If the material web rolls are also packaged in the winding bed, the rail can be used for guiding the packaging web dispenser which would have otherwise had no purpose. Also, the arrangement of the packaging web dispenser above the material web rolls to be packaged is advantageous in that the beginning of the packaging web hangs down because of gravity and thus can easily be guided to the circumference of the material web roll stack with relative ease.
The cutting device may be arranged on the rail, whereby the rail may thus provide a third function. The cutting device preferably has a circular blade that is generally radially movable toward and away from the stack. The circular blade xe2x80x9crollsxe2x80x9d with its sharp edge on the circumference of the packaged material web rolls, cutting through the packaging web. It is not necessary for the circular blade to cut through all layers of the packaging web in a single cut. It is also possible to rotate the stack when cutting the packaging web until the blade has penetrated all layers. The position of the circular blade must align in registry with the position of slitting station blades. If necessary, the cutting process can be automated, for example, through a shared control device that determines the positions of the blades in the slitting station and the circular blades in the cutting device.
The rail may carry a loading roller, which, during packaging, forms a nip with the stack through which the packaging web runs. A loading roller is already present in many winding devices, as explained supra. The loading roller may additionally be used to press the packaging web against the circumference of the material web roll during wrapping.
In a second embodiment, provision is advantageously made for the packaging web to have the same web path, at least in part, as the material web. For example, this arrangement allows the tension in the outer layers of the material web rolls and the tension in the packaging web to be matched so that no damage is caused by respective differences in tension. Moreover, dual use can be made of guide devices that are required for guiding the material web or the strips.
It is also advantageous if the cutting device is formed by the slitting station. The circumferential wrapping of the individual material web may thus have approximately the same width as the material web rolls themselves (e.g., the width of the strips) despite use of a helical packaging process.
It is further advantageous if the slitting station has a sensor that detects the passage of the leading side edge of the packaging web. Using the sensor, additional measures may be taken to re-attach the packaging web in the region of the leading edge. Further, the device can be configured so that the blade does not cut through the packaging web at all. If, for example, the slitting station works with top and bottom blades, it is possible to configure the device to wait to bring the top and bottom blades together until after the packaging web has run through the slitting section. The two packaging web sections may then remain connected over a distance of a several centimeters, which is inconsequential because this connection tears apart when the material web rolls are ejected from the winding bed.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings.